Slide mount



A. B. Fox 2,592,262

SLIDE MOUNT Filed March l0, 1948 Q l/ Z4 K l (f, FIG. 5. 78 17 Z I8 Z0 34 )ZZ 35 77 ARTHUR B. Fox

Y INVENTOR Patented Apr. 8, 1952 UNITED STATES PATENT OFFICE SLIDE MOUNT Application March 10, 1948, Serial N o. 14,069

14 Claims.

The present invention relates to a slide mount for holding a film transparency for viewing and/or projecting.

Two general types of mounts are vnow in use for mounting or holding transparencies. The rst type comp-rises a mount having overlying paper members between which the transparency is positioned or sandwiched. The members of the mount are formed with registering apertures which serve to frame the image-bearing portion of the transparency. When a plastic material is used instead of paper, one of the members may be eliminated and the transparency held in a seat in the other member by means of bent-over edges or beads. However, with both paper and plastic mounts, the emulsion of the transparency is unsupported and is exposed and may be damaged, as is apparent. Also, in case of paper mounts, dirt may adhere to the lm due to electro-static attraction. In addition, the edges of the paper mounts may become frayed when used in an automatic slide changer, and such frayed edges may interfere seriously with; and, in-extreme cases, may prevent feeding of the mount. Finally, while such paper or plastic mounts have had a fair degree -of success when used with low-wattage projectors, they are far from satisfactory when used in connection with lamps of high wattage.

v'Ihese high wattage lamps cause the film or transparency to buckle, and thus throw it out of. focus, the disadvantages of which are well known to those who use such mounts.

In order to overcome some of these difficulties, mounts are also provided in which the transparency is positioned or sandwiched be tween two layers or sheets of glass. These glass sheets serve to support and strengthen the transparency and thus greatly reduce and may even do away with the buckling problem. However, when such mounts are used with high wattage lamps, the heat incident thereto often causes lthe solvents and/or moisture in the nlm to boil out and then condense to form a fog or blemish on the transparency, the disadvantages Aof which are deemed to be obvious. In addition,

relation by'means of binding tape applied to the edges of the glass plates. This binding tape often binds or jams when the mounts are used in connection with an automatic slide changer. Finally, such double glass mounts are quite heavy.

In order to provide an effective support `for the transparency, yet eliminate the disadvantage of paper, plastic and double glass mounts, a new technique has recently been developed for mounting transparencies. This technique embodies the direct cementing of the emulsion of the transparency to the surface of a gelatincoated glass plate. In this procedure, a solvent or softening agent is applied to the emulsion of the transparency and also to the gelatin on the glass surface. The emulsion side of the transparency is then placed face down on the gelatin layer of the plate and pressure is then applied to the assembled structure to cause a binding of the emulsion to the gelatin layer. It has been found that with such an arrangement, the transparency is secured to and supported by the glass plate, and may be readily handled in a slide projector having a high wattage lamp. The emulsion side of the transparency is protected against damage, while the back is exposed to facilitate proper cooling.

The advantages of this new cementing technique are utilized in the mount of the present invention. To secure this result, a clear rigid transparent plate is preheated;` and a mask equal in size to the image area of the transparency, is then placed centrally on one surface of the glass plate. A layer of opaque metal is then applied to the balance of the glass surface to provide an opaque coating thereon. This metal is preferably applied by spraying, the

glass being rotated during such application. While various low melting point metals may be used, it is preferred to employ aluminum because of its cheapness and its heat-reecting characteristics. This aluminum is sprayed in a thin layer, approximately .0005 inch in thickness, over the surface of the-glass not protected by the mask. The latter is then removed to expose an uncoated section which is equal in size to the image-bearing area of the transparency.

A second mask equal in size to the dimensions of the transparency is positioned on the coated surface to overlie and in substantial concentric relation with the uncoated section. A second layer of sprayed aluminum is then applied to the rst layer to cover all the portions thereof not protected by the second mask. During this second coating operation the glass plate is also rotated, as in the rst coating, and the metal spray gun is directed at an angle to the surface and is positioned near the edge of the glass plate. Such an arrangement builds up a heavier deposit near the edge of the glass plate tapering toward the edge of the second mask. In addition, a layer of sprayed metal is applied to the edge of the glass plate to eliminate sharp edges and corners, the advantage of which will be readily apparent to those in the art. This second coating or layer is much thicker than the initial coating, being about .008 to .010 inch in thickness. When the second mask is removed a seat is formed at the juncture of the two coatings. This seat is of a size to readily receive the transparency. A portion of the bottom fthis seat is covered by the first coating and underlies the marginal or non-image bearing portions of the transparency so that only the image area ofu the latter is framed bythe uncoated section.

These sprayed coatings afford sharp clear edges, the advantage ofV which will be readily appreciated. A layer of adhesive, such as gelatin, is then applied over the bottom of the seat. The emulsion side of the transparency and the gelatin are treated, as above described, and the lm isplaeed emulsion sidedown on thegelatin so as to adhere thereto and form a secure bond therewith to attach the transparency securely to the glassl plate. The second coating extends above the back of the transparency and thus. protects the latter.. when the slides.'Y are stacked or moved in a slide changingapparatus. Preferably, thesecond layer gradually increases in thickness from the edge ofthe transparency to the edge of the glass plate.

"The invention has, therefore, as its principal object, a one-piece slide mount which adequately'protects the nlm or transparency against scufing", vand prevents buckling thereof when used in highwattage projectors.

Still another object of the invention is the provision of a mount which is less vsubject to breakage than VoneV protected by a loose mask and binding tape.

Another object of the inventionis the provision of amount of a simple construction so that even if broken, the piecesfwill hold together and permit the removal of the transparency for remounting.

` A, further object of theinvention is the provision of a mount which provides a desirable'support, for thetransparency yet permits adequate cfooling thereof.

' To these and other ends, the invention resides in` certain improvements and combinations of parts, allwill'be hereinafter more fully described, the novel features being pointed out in the claims atthe end ofthe specification.

Inthedrawings.:

Fig. 1 is a perspective view of a glass slide mount4 constructed in accordancewith theY preferred embodiment of the invention;

Fig. 2 is a sectional view through a portion of aA transparency used in connection with the mount of the present invention showing the relation of the emulsion layer;

Fig. 3is a side elevation view of a mount showing the rst steps in its formation;

Fig 4 is a view similar to Fig. 3, showing the second step in the mount formation;y

Fig. 5 isa view similar to Figs. 3 andfl, but on alarge'r' scale than therlatter, showing the relation of the mountl parts with the adhesive layer for securing the transparency of Fig. 2 in position in the mount; and

Fig. 6 is a view similar to Fig. 5 showing the transparency in position to complete the mount structure.

Fig. '7 is a partial sectional view through a modied slide construction.

Similar reference numerals throughout the various views indicate the same parts.

The mount of the present invention is primarilydesigned for use in connection with a positive film transparency which may be either black-and-white or colored. Such a transparency comprises a transparent base or support II, one face of which is coated with a sensitized emulsion layer I2, the central portion I3 of which carries the image. The marginal or non-imagebearing portions I4, on the other hand, are usually covered during projecting, as is well known. As such transparencies may be of any suitable and well known construction, and donot, perse, constitute a part of the present invention, further detailed description or illustration thereof are not deemed necessary.

The structural features of the mount will first be described, after which the method of formation of the mount will then be set forth. The slide mount comprises a clear rigid transparent base or support of the desired size and any suit- `able material such, for exampleI a glass plate Il. In order that the image-bearing portion I3 of the transparency may be projected whilev the marginal non-image-bearing portions I4 are blocked or masked off, the glass plate I l has the marginal portions of the surface I8 coated with an opaque material so as to leave a clear uncoated section I9 which is equal in size to and adapted to frame the image-bearing portion I3 of the transparency. The portions of thesurface I8 immediately adjacent the uncoated sec,- tion I9 are provided with a thin opaque layer 20 which effectively masks 01T the marginalv p0rtions I4 of the transparency, as is clearly illustrated in Fig. 6. This layer 20, as statedabove. is approximately .0005 inch in thickness and is equal in size to the dimensions of the transparency. The balance of the surface I8 is then provided with a thicker opaque coating 2 I (.008 inch to .010 inch in thickness) which terminates at the layer 20 to provide a recessed seat 22 adapted to receive the transparency, as best shown in Fig. 6. This thicker coating projects above the back 23 of the transparency to protect the latter, and preferably increases inv thickness as it approaches the outer edge 24 of. theplate This` thicker coating is also extendedV down over the edge, as shown in 25, to coverA the latter to eliminate sharp edges or corners, the advantage of which will be deemed apparent.

While the layer 20 and coating 2Irmay be applied in` any suitable manner, they are preferably applied bythe well known spray gun.y method. Any suitable low melting point metal such as solder, lead or tin may be used, but it is preferred tol employ aluminum not only because of Vits cheapness but also because of its good heat-refleeting characteristics. Before the metal is sprayed on the glass plate, the latter` is heated so as to eliminate thermal shock. A mask 28, equal in size tothe portion I3, is positioned centrally on the surface I8 of the glass plate I1. Handling means such as a post 29 may be secured to the mask 28 to facilitate handling thereof. Avmetal spraygun 30, positioned as shown in Fig. 3.' and supplied with aluminum in a well known manner,

directs the aluminum spray towards the surface I8 to coat the latter at all points except that covered by the mask 28. As mentioned above, this layer is relatively thin, being only about .0005 inch in thickness. This layer extends slightly over the upper corner of the plate, as shown at 3|, Fig. 3.

The mask is then removed leaving the thin layer 20 and the uncoated section I9, Fig. 3. A second mask 32 of a size equal to that of the transparency is then placed on the plate I8 to overlie the section I9 and the adjacent portions of the layer 20, as shown in Fig. 4. A separate and thicker coating 2| of sprayed aluminum is then applied to the balance of the layer 20 not protected by the mask 32. In this second spraying ing operation, the spray gun 30 is positioned as shown in Fig. 4 so that a portion of the sprayed metal will cover the edge 24 of the plate Il. During both spraying operations, the glass I1 is rotated to insure an even coating.

The mask 28 serves to provide a sharp inner edge 33 for the layer 20 to clearly frame the image-bearing section I3 of the transparency. The mask 32, on the other hand, provides a square sharp shoulder 34 which positions the transparency accurately in the seat 32, as is apparent from an inspection of Fig. 6. In order that the transparency may be held securely in the seat 32, a layer of gelatin 35 is applied in the manner shown in Fig. 5. The emulsion I2 of the transparency and/or the gelatin layer 35 are treated with a suitable solvent or softening agent, such for example, as a water and alcohol solution. The emulsion I2 is then placed face down on the gelatin layer 35, as shown in Fig. 6, to adhere the transparency thereto so as to securely retain the transparency in position in the seat 32.

The present invention thus provides a mount in which the emulsion of the transparency is protected while the back is exposed to facilitate cooling during projection. The glass plate also affords the desired support for the transparency and retains the latter against buckling when used with high Wattage lamps.

In the preferred embodiment, the second coating 2I is applied by spraying. Fig. 7, however, shows a modified arrangement of applying this second coating which is in the form of a sheet of metal 40, of suitable thickness, formed with a central aperture 4I equal in size to the seat 22. This metal sheet is provided with down turned edges 42 which overlie the edges 24 of the glass plate I1 to position the sheet on the glass plate. The slide with the sheet 40 in position thereon is then passed through an oven to fuse the sheet 40 to the sprayed layer 20 to provide, in effect, a single coating. The metal sheet 40 may be formed by punching or any other suitable method.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive idea may be carried out in a number of Ways. This application is, therefore, notl to be limited to the precise details described but is intended to cover all variations and modifications thereof falling within the scope of the appended claims.

I claim:

' 1. A slide mount comprising, in combination, a rigid transparent support one surface of which is provided with a clear central portion adapted toframe an image area formed in an emulsion layer positioned on one side of a transparency, a thin opaque layer of metal on said surface surrounding said portion commensurate with and adapted to support the part of said transparency outside of said area, a thicker layer of metal applied to the part of said surface not occupied by said transparency, said transparency being positioned on said support with the emulsion side thereof toward said surface, and a layer of adhesive positioned on said portion and said first layer to secure said side thereto.

2. A slide mount comprising, in combination, a rigid transparent support one surface of which is provided with a thin area of metal commensurate with and adapted to support the marginal portions of a transparency one side of which has applied thereto an emulsion layer having an image-bearing part, a clear uncoated section inside said area to frame the image bearing part of said transparency, a thicker metal coating applied to the balance of said surface outside said area, and an adhesive layer positioned on said area and section to secure the emulsion side of said transparency thereto. l

3. A slide mount comprising, in combination, a rigid transparent support, a metal coating applied to a surface of said support and formed to provide a recessed seat adapted to receive a film transparency one side of which has applied thereto an emulsion layer having an image section, a thin opaque metal layer around the edges of said seat to support the marginal portions of said transparency above said surface, a central uncoated area in said seat for framing the image section of said transparency, said transparency being positioned in said seat with the emulsion side toward said surface, and an adhesive layer for securing said emulsion to the area and layer.

4. A slide mount comprising, in combination, a rigid transparent support, a metal coating applied to a surface of said support and formed to provide a recessed seat adapted to receive a lm transparency one side of which has applied thereto an emulsion layer having an image section, a thin opaque metal layer around the edges of said seat to support themarginal portions of said transparency above said surface, a central uncoated area in said seat for framing the image section of said transparency, said coating projecting above said transparency when the latter. is positioned in said seat, said transparency being arranged in said seat with the emulsion side toward said surface, and an adhesive coating applied over said layer and area to secure said emulsion thereto.

5. A slide mount comprising, in combination, a rigid transparent support, a metal coating applied to a surface of said support and formed to provide a recessed seat adapted to receive a lm transparency, a thin opaque metal layer around the edges of said seat to support the marginal portions of said transparency above said surface, a central uncoated area in said seat for framing the image section of said transparency, said coating extending above said transparency at the edges of said seat and increasing in thickness toward the sides of said support, said transparency being arranged in said seat with its emulsion side toward said surface, and an adhesive layer positioned between said emulsion and said layer area to secure said emulsion thereto.

6. A slide mount comprising, in combination, a rigid transparent support, a low melting-point metal coating on a surface of said support and arranged to form a recessed film-receiving seat adapted to receive a transparency positioned in said seat and provided with an emulsion side towardsaid surface, said emulsion' side having an image area, a thin layer of a low-meltingpointmetal applied tosaid surface around the edges of said seat to receive the marginal portions of said transparencyto support the latter `above said surface, a central uncoated section in said seat to frame the image area of said transparency, said coating extending above said film at said seat and increasing in thickness toward the edges of said support, and an adhesive coatingon said layerand4 section to secure said emulsionside thereto.

7. A slide mount comprising, in combination, a transparent glass support, a sprayed aluminum coating on a surface of said support arranged toA provide a central recessed seat adapted to receive a nlm transparency arranged in said seat with the emulsion side positioned toward said support, a clear uncoated central portion in said seat for framing the image-bearing area of said transparency, a thin sprayed-aluminum layer on said surface and covering the balance of said seat outside said portion, and a gelatin layer positioned on said portion and said thin layer for securing said emulsion adhesively thereto to retain said transparency in position in said-seat, said coating projecting above said transparency at said seat and increasing in thickness toward they marginal edgesv of said support.

8. A slide mount comprising, in combination, a rigid transparent support, a metal coating appliedto a portion of a surface of said support to form a central recessed seat of a size adapted to receive a transparency, a central uncoated section on said surface in said seat of a size equal t the imagearea of said transparency, and a metal layer of vless thickness than said coating applied to said surface around the edges of said section for supporting the edges of said transparencyv and for masking off said area.

9. A slide mount comprising, in combination, a rigidV transparent support, a thin opaque metal layer arranged centrally on a surface of said support and having a central uncoated section on said surface adapted to frame the image area ofl a transparency, said layer being equal to the size of said transparency and supporting the por tionsthereof outside said area, and a thicker layer or" metal applied to the balance of said surface outside said thin layer.

10. A slide mount comprising, in combination, a transparent glass support, a thin layer of sprayed metal applied to a surface of saidsupp ort to provide a central uncoated section equal in size to an image area of a transparency, said layer having dimensions commensurate with those of said transparency and supporting the latter outside said area, and a thicker layer of sprayed metal applied over the balance of said surface outside said layer.

11. A method of forming a slide mount comprising, providing a rigid heated transparent support, placing centrally over a surface of said support a mask equal in size to an image area of a transparency, applying an opaque molten metal coating over the portion of said surface not occupied by said mask, removing said mask to provide a central uncoated section on said support equal in size to said area, placing on said surface concentrically with the area occupied by said first mask a second mask larger than said first mask and equal in size to the transparency, applying a second opaque molten metal coating of a thickness greater than the` first coating over the balance-of said first coating not covered by said second-mask, removing said second mask to provide a seat which is equalin size to said transparency, and then positioning and adhesively securingv said transparency in said seat.

12. A method of forming a slide mount comprising, providing aheated transparent glass support, placing centrally over a surface of said support a mask equal in size to an image area of a transparency, spraying a thin layer of molten metal on the portion of said surface not occupied by said mask, removing said mask to provide a central uncoated section equal to said area, placing on said surface substantially concentrically with said section a second mask larger than said first mask and equal in size to said transparency, spraying a thick layer of molten metal over the portion of said surface not occupied by said sec-V ond mask, thenvremoving the second mask to form a seat equal in size to said transparency and providing positioning shoulders for said transparency, and then securing said transparency in position in said seat. n

13. A method of forming a slide mount comprising, providing a heated transparent glass support, placing centrally over a surface of said support a mask equal in size to an image area` of a transparency, spraying a layer of metal onthe portion of said surface not occupied by said mask, removing said mask toprovide a central uncoated section equal to said area, placing'on said surface substantially concentrically with said section a second mask larger than said first mask and equal in size to said transparency, spraying a second layer of metal over the porftion of said surface not occupied by said second mask, and then removing the second mask, applying alayer of adhesive over said sectionand said first layer, and placing said transparency over said section and layer with the emulsion side in engagement with said adhesive and said area registering with said section.

14. A method of forming a slide mount comprising, providing a heated transparent glass sheet, placing centrally on a surface of saidsheet a mask equal in size to an image area of a film transparency, spraying a layer of aluminum -over the portion of said surface not occupied by said mask, removing said maskl from said surface to provide a central uncoated section of a size equal tofsaid area, placing on said coated surface. and substantially concentric with said section a second mask larger than said first mask and equal to the size of said transparency, spraying a second layer of aluminum over the exposed part of said 'rstlayen removing said second mask, coat-4 ingsaid section and the` exposed part of saidiirst layer with a layer of gelatin, placingsaid transparency in position with the emulsionthereofin contact with said gelatin to adhere the transparency thereto- ARTHUR B.. FOX.,

REFERENCES CITED The following. references are ofA recordinthe file of this patent:

UNITED STATES PATENTS Number Name Date 291,544 Snell Jan. 8, 1884 785,534 Anderson Mar. 21, 1905 2,000,310 White et al. May 7, 1935 2,053,923 Stewart Sept. 8,- 1936 2,119,608 Stewart June 7, 1938 2,197,274 Menke Apr. 16, 1940 2,228,352 Hopiicld ,Jan. 14,` 1941 2,428,043 Searle Sept. 30, 1947 

